Two sources with ties to the leadership said separately Ling Jihua, 59, an ex-top aide to President Xi Jinping’s predecessor Hu Jintao, had apparently suffered a nervous breakdown, while Guo Boxiong, a former top general, was gravely ill with cancer.

The party announced an investigation into Ling in December. He was demoted in September 2012 from a ministerial-level job months after his son was killed in a deadly crash involving a luxury sports car.

“The pressure on Ling has been too great. He has never recovered from losing his son,” one source said on condition of anonymity.